Ask Tom: When was the last 'slam-dunk' white Christmas?

When was the last time we had multiple snowy days in December leading up to a "white" Christmas?

— Matt Balitewicz, East Chicago, Ind.

Dear Matt,

Chicago's last "white" Christmas was in 2013, but it took an eleventh-hour Christmas night snowfall to qualify. Chicago climatologist Frank Wachowski informed us that the city's last "slam-dunk" white Christmas was in 2010 when the city was hit by a 5-inch snowfall Dec. 4 and the snow cover remained until it all melted on a mild, rainy New Year's Eve with temperatures in the lower 50s. After the Dec. 4 storm, the city's snow cover dwindled to just an inch through midmonth but increased to 5 inches by Christmas Day in the wake of a series of Christmas week snowfalls that included nearly 3 inches on Christmas Eve and Christmas Day.